Terry Deloria has a doctorate in educational leadership. She is the superintendent of the Jefferson Union High School District in San Mateo County. This school year, she's adding another title to her resume, math teacher, and period one.

Jefferson Union High School District has five schools and adult education classes in Pacifica and Daly City.

San Mateo County is one of the most expensive places to live in the U.S. and being a teacher will not make you rich.

In fact, starting teachers at Jefferson Union make between $49,550 to $51,409. According to a recent survey by the National Low Income Housing Coalition, you'd need to make $124,840 a year to afford a two bedroom apartment in San Mateo County.

You do the math, and it just doesn't add up.

Terra Nova Teacher Marlene Guitierrez said, "So I'm still renting and I'm struggling. It's a challenge for me to come up with my rent money. It's almost 40 percent of my take home pay."

Guitierrez has taught at Terra Nova High School for 18 years. Because of the high cost of living, teachers in Jefferson Union are often times forced to live in less than ideal situations, like having several roommates, commuting from faraway places or even working a second job.

"You're not just tired physically, you're tired emotionally and mentally and you want to prepare new lessons, you want to prepare engaging lessons, how can you do that if you have to hurry to your next job?" said Guitierrez.

Jefferson Union says they've recently started to lose 1 out of 5 teachers every year. The revolving door is impacting the student's education.

"Well we spend our energies and resources in other areas rather than working or improving things in the classroom," said Dr. Deloria.

Finding math and science teachers is especially difficult. More chemistry teachers will be needed at Terra Nova next year. Three math teaching positions remain open in the district. If the statistics hold, 20 percent of the teachers in Jefferson Union will leave this summer.

"They may go somewhere else, they may leave the state, they may leave the profession altogether," said Deloria.